Category: Nature & Life

Polar bears (Ursus maritimus) are carnivorous marine mammals that prowl the ice sheets and coastal waters of the Arctic region. They have developed several key adaptations to thrive in the harsh cold of their northern habitat, including a thick, insulating layer of fat and a coat of white fur that not only provides camouflage in snow and ice, but also extends to the bottom of their paws to provide additional grip. Polar bears are excellent swimmers because of their elongated bodies and strong front paws, and are able to cross distances of up to several hundreds of kilometers in water. The animals have no natural enemies and primarily hunt for seals along the edges of the ice where their prey surface to breathe, but they are also known to feed on land mammals or the carcasses of whales. After mating in spring, female polar bears set out to gain weight and dig a den in the snow, where they enter a hibernation-like state and give birth in winter, generally to a litter of two cubs. They raise their young for a period of approximately two and a half years without the help of males, boldly protecting them against the elements and threats, such as wolves and other polar bears.

Red foxes (Vulpes vulpes) are the largest of all foxes and live in many diverse habitats around the world, including forests, grasslands, mountains, deserts and even human environments. They generally have a red or brown colored fur, with traces of white on their chin, throat, chest and tail. Red foxes are omnivores with a highly variable diet, feeding on rodents, rabbits, birds and other small animals, as well as plants, fruits and human leftovers, depending on availability. The animals are most active between dusk and dawn, and while they typically forage on their own, red foxes are known to live together in pairs or in small families. They breed in winter, after which the females, or vixens, give birth to litters of up to twelve pups in spring. The young foxes are raised by both parents and may leave the litter in the following fall to establish their own territory if conditions are favorable, or stay behind to help raise subsequent litters. Because of their inventiveness and ability to adapt to new environments, foxes have traditionally been associated with intelligence and cunning.

Information sources: National Geographic, WWF

Image: Red fox sniffing the air in the grasslands of San Juan, Washington, USA. Credit: Minette Layne, Wikimedia Commons.

Black smokers are hydrothermal vent structures that discharge hot, dark fluids from the ocean floor. They generally form near areas with submarine volcanic activity, such as mid-ocean ridges, where hydrothermal fluids circulate through the oceanic crust and exchange elements with the surrounding rocks. As these hot fluids come into contact with the much colder seawater, the dissolved minerals precipitate into particles and may form spectacular chimney-like structures.

The waters surrounding hydrothermal vents are often very hot and acidic, but nevertheless life is able to thrive under these extreme environmental conditions. Select groups of bacteria, known as extremophiles, can survive in these hostile environments and are capable of harnessing the hydrogen sulfide (H2S) emitted by black smokers as an energy source through chemosynthesis. These bacteria subsequently attract and are eaten by higher organisms, such as crustaceans, worms, molluscs and fish. As a result, hydrothermal vents may form the basis of entire ecosystems that are independent of solar energy. The biodiversity of ecosystems near black smokers is even thought to be higher than in the rest of the deep ocean.

For more information on black smokers and how they form, check out this article on SeaRocksBlog.org.

Cheetahs (Acinonyx jubatus) are the fastest land mammals on Earth and live in the open grasslands of most parts of sub-Saharan Africa and Iran. They are characterized by a golden fur covered with small, black spots and prey on smaller herbivores such as antelopes and hares. Because of their light and agile build, cheetahs are able to accelerate from 0 km/h to 100 km/h in 3 seconds and run at incredible speeds of up to 120 km/h over short distances. Chasing prey costs massive amounts of energy and requires so much of their bodies that cheetahs even risk brain damage at the end of a chase. As a result, they have to rest and recover in the shadow after each endeavor, during which they are mostly unable to defend themselves or their prey against other predators. Male cheetahs are often social and may live in groups to establish a territory and even hunt together, but female cheetahs are mostly solitary and hunt alone. Females raise their cubs on their own and leave them behind once the young become independent of their mother. Subsequently, female cubs leave the litter as well, but male cubs may remain together for the rest of their lives.

African lions (Panthera leo) are apex predators that live in the barren savanna grasslands of most parts of sub-Saharan Africa, blending in well with the surroundings because of their golden fur. They feed on large herbivores such as wildebeest, zebras, buffalo, warthogs and gazelles, as well as smaller rodents. Lions are the only cats that live together in groups, called prides, which may consist of up to three males, ten lionesses and their young. They rest for most of the day, but are generally active at dusk and during the night. Male lions are known for their long manes and defend the territory of the pride against rivals, while the lionesses are the main hunters and stalk their prey in groups before closing in for a kill. As they grow, young males leave the pride to establish their own, while females often stay behind. Historically, the lion has been regarded as the king of beasts and is therefore still used as a symbol of courage, strength and royalty.

Emperor penguins (Aptenodytes forsteri) are the largest of all penguins and are adapted to the extreme cold of the ice sheets of Antarctica and the surrounding seas. They are characterized by a black head and backside, with a hint of yellow on their breast and behind their ears. Because of their streamlined bodies and strong flippers, emperor penguins are excellent swimmers, and at sea they can dive to a depth of more than 500 meters, deeper than any other bird. As carnivores, emperor penguins prey on fish, squid and krill, while they are hunted by leopard seals and killer whales as well as large seabirds, which scavenge mainly on chicks. They are very social animals that huddle together in large colonies in order to survive the harsh conditions of their icy environment. Emperor penguins breed in winter and while females go hunting in the Antarctic waters for themselves and their unborn chicks, males keep the eggs warm in brood pouches on top of their feet. Male and female emperor penguins stay together during the full breeding season, but some are even rumored to remain faithful to their partners for life. After an egg hatches, the parents of the newly born chick take turns foraging at sea and raising their chick in the colony.